NO passenger tires on CTD
Get ride of those tires immediately, Do not pass Go-- Do it today your life may be at stake!!!!!
When we bought our '99 2500 CTD, the wife wanted larger tires to fill the wheel wells. The dealer put on P-metrics from a 1500 265/75R16. In 10,000 miles we had 3 flats. At 15,000 miles we had 2 flats in one day!! We were on a graded gravel road and lucky to have been going 20 MPH when we had a massive blow out (rear). Changed the tire and 2 hours later had a massive blowout as we turned into a campground on grass (Driver front). We were 30 miles from the nearest gas station and borrowed a recap mounted on a Ford Wheel. (sometimes glad a Ford is around

) just to get home. Went to Big O and got 4 new tires. Boy ere they surprised I had P-Metrics and pointed out the load capacity was way under the front axle weight. They were shocked the dealer put these tires on this truck (CTD) but OK for the 1500's.
I went to the dealer with two tires that looked like they came off a Ford Explorer. The tread was ripped away from the belts and the belts were ripped away from the sidewalls on one and the other in addition to the tread ripped away the tire was almost split from the tread to the rim bead.
I had problems with the parts manager and service writers. I was stonewalled for 3+ months. So I went to the manager and brother of the owner. We went back into parts and I showed him the tires. He bought me new custom aluminum wheels, paid for a major service and issued a memo to never put P-metrics on a CTD. I went back to parts the next day and the tires were gone!!! I didn't want to sue, just make sure they didn't put P-metrics on another CTD. But obviously they got rid of the evidence ASAP, I could have owned a Dodge Dealership!!
Your life is not worth the risk of running P-metrics. I had been driving 70+ on 2 lane mountain highways and passing others. I wouldn't be able to tell you these things had the tires failed the day before and 50 miles sooner!!
Let us know you are safe with LT tires
doc